Can't sign in to browser and Bing keeps hijacking search

Hello, been through hell with this browser and don't want to waste any more time. I cannot sign in to the browser since a few days ago, tried the beta, different versions and nothing works.

Also, I know bing is paying you guys to include it but does it have to be damn malware? I have google as my default search like everyone else in the world but every search literally switches from google's engine to bing right before my eyes. You did oyur job, you got your sponsor money but why does it have to take over my browser? Do not waste my time with default blah blah blah please Bing is NOT my default search...google is. It is hijacking every search attempt like a virus...just tell me how to disable bing entirely, thanks.

@leocg I don't know why the sign in does not work...i looked around and it's a common problem with no solution ever posted in any thread. It's common, hopefully you can tell my why your browser's sign in function is broken.

As far as the search engine change, it happens on a completely fresh install of opera with NOTHING added to it and in fact, this is a fresh install of Windows 10.

@leocg I physically see a google search starting, then a half second into the search before results are displayed the whole web page literally switches to bing from google. Anyway, I am going to use a different browser for now.

@leocg I physically see a google search starting, then a half second into the search before results are displayed the whole web page literally switches to bing from google. ...

This sounds so much like a browser hijacker that it's scary, possibly one located in a rogue extension or a malicious redirection entry in the OS hosts file. Does anything like this happen with a native browser (IE or Edge)? When you stated this is a "fresh install" of Win10, did you mean a total main-drive disk reinstall from a previously-made image, a re-install from an OEM OS partition, a Win10 repair install, or something else? Also, when you stated this was a "completely fresh install of Opera", did you mean you wiped out all the original Opera user profile files along with the old installation before reinstalling?